A monochorionic diamniotic (MCDA) twin pregnancy is a subtype of monozygotic twin pregnancy. An MCDA pregnancy results from a separation of a single zygote at ,4-8 days (blastocyst) following formation. These fetuses share a single chorionic sac but have two amniotic sacs and two yolk sacs. It accounts for the vast majority (70-75%) of monozygotic twin pregnancies although only ,30% of all twin pregnancies. The estimated incidence is at ,1:400 pregnanciesThe layman term is that the twins are identical – in reality, they are phenotypically similar, and of course of the same gender.

Among the given options, the inability to grip a sheet of paper between his fingers when the hand is placed flat on the table is the feature of ulnar nerve injury. Rationale:The ulnar nerve (usually) supplies sensation to the skin of the fifth and the ulnar side of the fourth finger, front and back. Following the injury of the nerve, the following functions are impaired:- There is a sympathetic interruption, with the absence of sweating in the affected area. – The thenar muscles are supplied by the median nerve and are therefore spared. – The ulnar nerve also supplies the muscles of the hypothenar eminence. – Although the ring and little fingers are held in the clawed position when the nerve is injured at the wrist, a high lesion paralyses the long flexors to these two fingers and results in the loss of this sign. The test for paralysis of the palmar interossei, supplied by the ulnar nerve, is the inability to adduct the fingers and thus to be unable to grip a sheet of paper between them.

A ventricular septal defect (VSD) is a common form of congenital heart defects and is characterised by the presence of a hole in the wall that separates the right from the left ventricle. Medium or large defects can cause many complications. One of these complication is Eisenmenger syndrome, characterised by reversal of the shunt (from left-to-right shunt into a right-to-left) ,cyanosis and pulmonary hypertension.

The trigeminal nerve is responsible for the sensory innervation of the head, and the muscles of mastication. The nerve is divided into three branches, the ophthalmic nerve (V1) the mandibular nerve (V2) and the maxillary nerve (V3) which all exit the skull through their respective foramina. An easy way to remember these foramina is with the following mnemonic:Standing Room Only, for V1-V3 respectivelyV1- Superior orbital FissureV2- foramen RotundumV3 foramen Ovale

The most probable diagnosis for this patient is Maple syrup urine disease (MSUD).Note:- Healthy new-borns have blood sugars between 3.3 and 5 mmol/L- Neonatal hypoglycaemia is glucose < 2.2 mmol/L if measured in the first 3 days of life.- Neonatal hypoglycaemia is glucose < 2.5 mmol/L after the first 3 days of life.Causes of persistent hypoglycaemia include:- Preterm- IUGR- SGA- Hyperinsulinism due to maternal diabetes- Beckwith-Wiedemann syndrome- Hypoxia at birth- Sepsis- Cardiopulmonary disease- Inborn errors of metabolism- Hepatic enzyme deficiencies- Glycogen storage disease

Pupils are dilated in patients with amitriptyline overdose.Tricyclic antidepressants have a narrow therapeutic index, and thus, small doses can be fatal in children. Deaths from tricyclics are more common than other antidepressants. Bimodal incidence with toddlers (accidental) and teenagers (deliberate) most commonly affected.Symptoms: They occur within 6 hours of ingestion.- Nausea, vomiting, and headache- Elevated body temperature- Agitation, sleepiness, confusion, coma- Dry mouth, blurred vision, urinary retention (anticholinergic)- Dilated pupils- Seizures- Hypotension, tachycardia, conduction disorders, and cardiac arrest- Respiratory depressionManagement:Treatment focuses on supportive care. This includes airway protection, ventilation and oxygenation, intravenous fluids, and cardiac monitoring.Other measures include:- Activated charcoal within 2 hours- Hypotension is treated with IV fluids and adrenaline- Cardiac monitoring- Sodium bicarbonate in acidosis or if there are wide QRS complex (> 100 ms)- Convulsions may require diazepam or lorazepam.

Maternal and fetal toxoplasma infection may be avoided by advising pregnant women to wear gloves when gardening or handling cat litter and to cook meat thoroughly. Affected babies are treated with pyrimethamine, sulfadiazine, and folic acid.

Fluid replacement therapy should be initiated immediately because the patient is suffering from severe dehydration as shown by the low urine output, the dry mucous membranes and the low skin turgor.

CMPI ( cow’s milk protein intolerance) is an immunological reaction to one or more of the many proteins found in cow’s milk. It may be IgE mediated or non-IgE mediated. The prominent signs and symptoms include sneezing, rhinorrhoea, coughing, wheezing, oral angioedema, oral itching, diarrhoea, vomiting, and bloody stools. Steatorrhea is not a recognized feature of CMPI.

The presentation of the child is highly suggestive of Henoch-Schonlein purpura (HSP). It is an IgA-mediated, autoimmune hypersensitivity vasculitis that targets the small vessels of the skin, GI tract, kidneys, and joints.It is most commonly seen in children aged 3 – 6 years old and is twice as common in boys than girls. Preceding viral URTI with low-grade pyrexia is common. The most common organism associated with HSP is, however, Group A streptococcal infection.A purpuric rash is seen on the back of the legs and buttocks and can less frequently affect the arms. Arthralgia is common (usually knees/ankles) in these patients.Abdominal pain and bloody diarrhoea may occur. And half of the children with HSP have renal involvement. Rarely, it can lead to end-stage renal failure.Treatment includes adequate hydration, occasionally steroids, and other immunosuppressants. The disease can recur in 1 in 3 children.

The boy needs re-hydration due to his full thickness burn so IV fluids is the next most appropriate step. The greatest loss of plasma occurs in the first 12 hours after burn injury. The plasma loss then slowly decreases during the second 12 hours of the post-burn phase, although extensive leakage can continue for up to three days (Ahrns, 2004). Optimal fluid replacement during this period is essential to ensure cardiac output and renal and tissue perfusion. Usually, 36 hours post-burn, capillary permeability returns to normal and fluid is drawn back into the circulation. Burns of more than 15% of surface body area in adults and of over 10% in children warrant formal resuscitation.The Parkland formula for the total fluid requirement in 24 hours is as follows:4ml x TBSA (%) x body weight (kg)|50% given in first eight hours|50% given in next 16 hours.Children receive maintenance fluid in addition, at an hourly rate of:4ml/kg for the first 10kg of body weight plus|2ml/kg for the second 10kg of body weight plus|1ml/kg for >20kg of body weight.End pointUrine – adults: 0.5–1.0 ml/kg/hour|Urine – children: 1.0–1.5ml/kg/hour.

Developmental dysplasia of the hip (DDH) is a spectrum of anatomical abnormalities of the hip joint in which the femoral head has an abnormal relationship with the acetabulum.Plain radiographs are of limited value for diagnosis in the new-born child because the femoral head and acetabulum are largely cartilaginous. Ultrasound scanning is the investigation of choice to evaluate DDH in infants younger than six months of age and is useful to diagnose more subtle forms of the disorder when a clinical exam is equivocal. It is also the only imaging modality that enables a three-dimensional real-time image of a neonate’s hip.

Oesophageal atresia refers to a congenitally interrupted oesophagus. One or more fistulae may be present between the malformed oesophagus and the trachea. The lack of oesophageal patency prevents swallowing. In addition to preventing normal feeding, this problem may cause infants to aspirate and literally drown in their own saliva, which quickly overflows the upper pouch of the obstructed oesophagus. If a tracheoesophageal fistula (TEF) is present, fluid (either saliva from above or gastric secretions from below) may flow directly into the tracheobronchial tree.The complete absence of gas in the GI tract denotes the absence of a distal tracheoesophageal fistula (TEF)| however, distal fistulae simply occluded by mucous plugs have been rarely reported.If no distal TEF is present, a gastrostomy may be created. In such cases, the stomach is small, and laparotomy is required. In all cases of oesophageal atresia in which a gastrostomy is created, care should be taken to place it near the lesser curvature to avoid damaging the greater curvature, which can be used in the formation of an oesophageal substitute. When a baby is ventilated with high pressures, the gastrostomy may offer a route of decreased resistance, causing the ventilation gases to flow through the distal fistula and out the gastrostomy site. This condition may complicate the use of ventilation.

The given presentation is highly suggestive of withdrawal effect of ketamine.Ketamine is known for its unique property of inducing dissociative anaesthesia. Emergence phenomenon (as seen in the child in question) is an adverse effect that occurs during recovery from dissociative anaesthesia. The components of emergence phenomenon include a euphoric state associated with hallucinations.

The glossopharyngeal nerve is the primary sensory nerve for the tonsillar fossa. The lesser palatine nerve makes a smaller contribution. Because of this, otalgia may occur following tonsillectomy.Anatomical Rationale:Each palatine tonsil has two surfaces, a medial surface which projects into the pharynx and a lateral surface that is embedded in the wall of the pharynx.The primary arterial supply is from the tonsillar artery, a branch of the facial artery. Its veins pierce the constrictor muscle to join the external palatine or facial veins. The external palatine vein is immediately lateral to the tonsil, which may result in bleeding during a tonsillectomy.Lymphatic drainage is the jugulodigastric node and the deep cervical nodes.TonsillitisThe inflammation of tonsils is usually due to bacterial aetiology (50%) – group A Streptococcus, the remainder of the causes are viral.May be complicated by the development of an abscess (quinsy), which may distort the uvula.Indications for tonsillectomy include recurrent acute tonsillitis, and enlargement causing sleep apnoea.Dissection tonsillectomy is the preferred technique with haemorrhage being the most frequent complication. Delayed otalgia may occur owing to irritation of the glossopharyngeal nerve.

Hirschsprung’s disease is characterized by congenital absence of the autonomic plexus (Meissner’s and Auerbach’s plexus) in the intestinal wall. Usually limited to the distal colon, it can occasionally involve the entire colon or even the small bowel. There is abnormal or absent peristalsis in the affected segment, resulting in continuous spasm of smooth muscle and partial/complete obstruction. This causes accumulation of intestinal contents and dilatation of proximal segment. Skip lesions are highly uncommon. This disease is seen early in life with 15% patients presenting in first month, 60% by 1 year of age and 85% by the age of 4 years. Symptoms include severe and complete constipation, abdominal distension and vomiting. Patients with involvement of ultra-short segments might have mild constipation with intervening diarrhoea. In older children, symptoms include failure to thrive, anorexia, and lack of an urge to defecate. On examination, an empty rectum is revealed with stool palpable high up in the colon. If not diagnosed in time, it can lead to Hirschsprung’s enterocolitis (toxic megacolon), which can be fulminant and lead to death. Diagnosis involves a barium enema or a rectal suction biopsy. Barium enema shows a transition in diameter between the dilated, normal colon proximal to the narrowed, affected distal segment. It is to be noted that barium enema should be done without prior preparation, which can dilate the abnormal segment, leading to a false-negative result. A 24-hour post-evacuation film can be obtained in the neonatal period – if the colon is still filled with barium, there is a high likelihood of Hirschsprung’s disease. Full-thickness rectal biopsy is diagnostic by showing the absence of ganglion cells. Acetylcholinesterase staining can be done to highlight the enlarged nerve trunks. Abnormal innervation can also be demonstrated by rectal manometry.

The presenting features and the surgical site provided in the clinical scenario are highly suggestive of ipsilateral hypoglossal nerve injury.Note:Three cranial nerves may be injured during submandibular gland excision.- Marginal mandibular branch of the facial nerve- Lingual nerve- Hypoglossal nerveHypoglossal nerve damage may result in the paralysis of the ipsilateral aspect of the tongue. The nerve itself lies deep to the capsule surrounding the gland and should not be injured during an intracapsular dissection. The lingual nerve is probably at higher risk of injury. However, the effects of lingual nerve injury are predominantly sensory rather than motor.Thus, the most appropriate answer is the hypoglossal nerve.

Haemophilia A and haemophilia B are inherited in an X-linked recessive pattern. The genes associated with these conditions are located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition.

The most common congenital cyanotic heart disease and the most common cause of blue baby syndrome, Tetralogy of Fallot shows four cardiac malformations occurring together. These are ventricular septal defect (VSD), pulmonary stenosis (right ventricular outflow obstruction), overriding aorta (degree of which is variable), and right ventricular hypertrophy. The primary determinant of severity of disease is the degree of pulmonary stenosis. Tetralogy of Fallot is seen in 3-6 per 10,000 births and is responsible for 5-7% congenital heart defects, with slightly higher incidence in males. It has also been associated with chromosome 22 deletions and DiGeorge syndrome. It gives rise to right-to-left shunt leading to poor oxygenation of blood. Primary symptom is low oxygen saturation in the blood with or without cyanosis at birth of within first year of life. Affected children ay develop acute severe cyanosis or ‘tet spells’ (sudden, marked increase in cyanosis, with syncope, and may result in hypoxic brain injury and death). Other symptoms include heart murmur, failure to gain weight, poor development, clubbing, dyspnoea on exertion and polycythaemia. Chest X-ray reveals characteristic coeur-en-sabot (boot-shaped) appearance of the heart. Treatment consists of immediate care for cyanotic spells and Blalock–Taussig shunt (BT shunt) followed by corrective surgery.

The most probable diagnosis for this patient would be Crohn’s disease.Crohn’s disease:An inflammatory bowel disease which can affect any part of the bowel from the mouth to the anus. Symptoms include abdominal pain, diarrhoea, pyrexia and weight loss. Extra-intestinal manifestations include arthritis, uveitis, fatigue, anaemia and rashes including pyoderma gangrenosum and erythema nodosum.Other options:- Anorexia nervosa is an important diagnosis to consider. There are no indicators in the description that she has a fear of gaining weight or a strong desire to be thin.- Diabetic ketoacidosis is incorrect because there is no polydipsia or polyuria. A patient in DKA is more likely to present with vomiting and not diarrhoea.- Recurrent aphthous stomatitis is not a correct answer because it does not explain all of the symptoms described, only the mouth ulcers.- Ulcerative colitis (UC) is also incorrect. UC is a form of inflammatory bowel disease that causes inflammation in the colon. The main symptom is bloody stools, which is not mentioned as a feature in history.

The structure in question is the rectus sheath. This sheath encloses the rectus abdominis muscle and thus, will be encountered by the surgeon.Note:- Midline incision: It is the most common approach to the abdomen. The structures divided during this incision are linea alba, transversalis fascia, extraperitoneal fat, and peritoneum ( with care taken to avoid the falciform ligament above the umbilicus).The bladder can be accessed via an extraperitoneal approach through the space of Retzius.- Paramedian incision: It is an incision that is made parallel to the midline. The structures divided or retracted are anterior rectus sheath, rectus (retracted), posterior rectus sheath, transversalis fascia, extraperitoneal fat, and peritoneum.- Battle incision: It is similar to a paramedian but the rectus is displaced medially (and thus denervated).- Kocher’s incision: It is an incision made under the right subcostal margin, e.g. cholecystectomy (open).- Lanz incision: It is an incision in the right iliac fossa, e.g. appendicectomy.Gridiron incision: It is an oblique incision centred over the McBurney’s point – usually used for appendicectomy (less cosmetically acceptable than LanzPfannenstiel’s incision: It is a transverse suprapubic incision, primarily used to access pelvic organs.McEvedy’s incision: It is a groin incision used for emergency repair strangulated femoral hernia.Rutherford Morrison incision: It provides an extraperitoneal approach to left or right lower quadrants. It provides excellent access to iliac vessels and is the approach of choice for first-time renal transplantation.

Based on the clinical presentation, the pubic hair development is in Tanner stage 2.The Tanner stages for pubic hair are as follows:Stage 1 – pre-adolescentStage 2 – sparse hair that is long, slightly pigmented and downyStage 3 – hair spread over the junction of the pubes, darker and coarserStage 4 – adult-type hair, but the area covered is smaller than it is in an adult.Stage 5 – adult in quantity and type

Because the initial chest X-ray returned an anomaly, a skeletal survey is the best option. Also known as a bone survey, the skeletal survey is a series of X-rays that will help analyse the structure of all the bones in the body. Because the child is not very active yet presents with bruising, the child protection register should also be checked but only after a skeletal survey has been conducted.

Androgen insensitivity syndrome (AIS), previously referred to as testicular feminization, is an X-linked disorder in which the patients are genotypically male (possessing and X and Y chromosome) and phenotypically female. This disorder is rare, with reported incidences from 1 in 20,000 to 1 in 60,000 live male births, and is the result of a missing gene on the X chromosome that is responsible for the cytoplasmic or nuclear testosterone receptor. In its absence, the gonad, which is a testis, produces normal amounts of testosterone| however, the end tissues are unable to respond due to the deficient receptors leading to the external genitalia developing in a female fashion. Anti-Mullerian hormone, which is produced by the testis, is normal in these patients, leading to regression of the Mullerian duct. Wolffian duct development, which depends on testosterone, does not occur as the ducts lack the receptors. The cumulative effect is a genotypic male with normal external female genitalia (without pubic or axillary hair), no menses, normal breast development, short or absent vagina, no internal sex organs, and the presence of testis. Frequently, these patients have bilateral inguinal hernias in childhood, and their presence should arouse suspicion of the diagnosis.

The main aim of randomisation in a clinical trial is to remove the bias and avoid any potential confounding variables. While in double blind studies both the investigators and the patients are not aware of which group they belong in, being blind is not essential in carrying out a randomized study, nor is it essential that the randomisation be done away from the study centre. A placebo also does not facilitate randomisation, which can be done in single centre and multi-centre trials.

This history is suggestive of Henoch-Schönlein Purpura following a respiratory infection. A typical rash involving thighs and buttocks is often seen in this age group. Coagulation profile is the suitable answer from the given answers.

Sturge-Weber syndrome is a genetic condition affecting various blood vessels. I causes brain, eye, and skin abnormalities, including three major features: port-wine birthmark, leptomeningeal angioma, and glaucoma. Most people are born with a port-wine birthmark that is usually located on the face, including the eyelid.

Neurofibromatosis Type 1 (also known as von Recklinghausen disease) does not present with cataracts.The eye findings in NF1 are Lisch’s nodules, which are pigmentary lesions seen on the iris and constitute one of the major diagnostic features in this condition. Note:Interestingly, in another syndrome closely related to it, Neurofibromatosis type 2 (NF-2), cataracts can occur. Early detection in family members may be made by finding lens opacities (both congenital polar cataracts and posterior lenticular opacities). Other options:- Incontinentia pigmenti is an X-linked dominant disorder with pigmentary skin changes, mental retardation and eye involvement in 40% of cases. – Myotonic dystrophy is a triplet-repeat disorder with neurological symptoms and cataracts. – Lowe syndrome (oculo-cerebro-renal syndrome) is an X-linked recessive condition. Males with this X-linked recessive condition have cataracts, hypotonia, mental retardation, generalised aminoaciduria and renal tubular acidosis with hypophosphatemia. – Wilson disease is an inborn error of copper metabolism. The clinical features include hepatic involvement, progressive neurological features, eye involvement, including Kayser–Fleischer rings and cataracts.

The most probable cause for chronic parotitis in this patient would be HIV infection.Rationale:Chronic infectious parotitis is relatively uncommon in children. While mycobacterial infection can result in chronic parotitis, HIV is a relatively more common cause. The presentation should always prompt an HIV test. Other options:- While mumps is the most common cause of acute viral parotitis, the chronic nature of the boy’s presentation rules it out. – Acute bacterial parotitis is usually unilateral and is warm and tender to touch.

The clinical presentation is typical of a slipped femoral epiphysis, which refers to a fracture through the growth plate (physis), resulting in slippage of the overlying end of the femur. It is the most common hip disorder in adolescence. SCFEs usually cause groin pain on the affected side, but sometimes cause knee or thigh pain. The range of motion in the hip is restricted in internal (medial) rotation, abduction, and flexion.